1. Field of the Invention
The present invention generally relates to the technical field of duplicating direct access storage devices. More particularly, the present invention relates to a method of duplicating hard disk drives used in personal computers and an apparatus for duplicating hard disk drives used in personal computers.
2. Description of the Prior Art
In recent years there has been a dramatic increase in the size of operating systems and application programs for personal computers (PCs). This has resulted in an increase of the size of direct access storage devices (DASDs), such as hard disk drives (HDDs) which are the most common mass data storage device for PCs. For example, Microsoft.RTM.'s Windows 95.TM. operating system and other application programs such as word processor, spread sheet, data base and Internet browser are typically all placed on a PC's HDD. It is common to have more than 300 Megabytes (MB) of "necessary" files for the most basic operation of the PC.
The loading of large amounts of data into the HDDs has became a real-life challenge. In many businesses, such as PC manufacturers and PC maintenance and service companies, it is often a task to load a large amount of the same data into multiple HDDs, or copy a large amount of data from a master HDD to a multiplicity of target HDDs. There is an increasing need for fast and reliable HDD duplicating devices which can be utilized to copy large amount of data from a master HDD to one or more target HDDs simultaneously.
The following prior art references are found to be pertinent to the relevant fields of art of the present invention:
1. U.S. Pat. No. 4,494,156 issued to Kadison et al. on Jan. 15, 1985 for "Selectable Format Computer Disk Copier Machine" (hereafter "the Kadison Patent");
2. U.S. Pat. No. 4,727,509 issued to Johnson et al. on Feb. 23, 1988 for "Master/Slave System For Replicating/Formatting Flexible Magnetic Diskettes" (hereafter "the Johnson Patent");
3. U.S. Pat. No. 4,862,411 issued to Dishon et al. on Aug. 29, 1989 for "Multiple Copy Data Mechanism On Synchronous Disk Drives" (hereafter "the Dishon Patent");
4. U.S. Pat. No. 4,864,431 issued to Murase on Sep. 5, 1989 for "Tape Dubbing Apparatus In Which Each Of A Plurality of Slave Recorders Is Operated In Synchronism With A Master Player" (hereafter "the Murase Patent");
5. U.S. Pat. No. 4,866,601 issued to DuLac et al. on Sep. 12, 1989 for "Digital Data Bus Architecture For Computer Disk Drive Controller" (hereafter "the DuLac Patent");
6. U.S. Pat. No. 5,167,020 issued to Kahn et al. On Nov. 24, 1992 for "Serial Data Transmitter With Dual Buffers Operating Separately And Having Scan And Self Test Modes" (hereafter "the Kahn Patent");
7. U.S. Pat. No. 5,235,683 issued Dahlerud on Aug. 10, 1993 for "Method And Apparatus For Accessing Peripheral Storage With Asychronized Individual Requests To A Host Processor" (hereafter "the Dahlerud Patent"); and
8. U.S. Pat. No. 5,241,526 issued to Ishii on Aug. 31, 1993 for "Recording Data Processing System For Optical Recording" (hereafter "the Ishii Patent").
The Kadison Patent discloses a selectable format computer disk copier machine. It uses a host computer, disk controller, disk drive, and mechanical disk feeder in order to automatically copy information onto each of a number of disks.
The Johnson Patent discloses a master/slave system for replicating/formatting flexible magnetic diskettes. It comprises a CPU section which has a Kopy Module and two associated manual modules, and is coupled by a daisy-chained bidirectional data Way to a plurality of slave stations. The Kopy Module stores a plurality of possible diskette formats as well as operator-introduced copy and duplicating instructions. Blank diskettes are fed into the slaves and the blank diskettes are formatted with information supplied by the master. A translator contained within the Kopy Module allows diskettes bearing all of the commonly used data encoding techniques to be replicated.
The Dishon Patent discloses a multiple copy data mechanism on synchronous disk drives. The system includes a host central processing unit (CPU) which is connected to control units and a plurality of direct access storage devices (DASDs) are predetermined to record the same data from the CPU. The DASDs are kept rotationally synchronized with one another except during the power up. The DASD synchronization is controlled and maintained by synchronization control means independent of any commands from the CPU. When one or more commands are transferred from the CPU to a control unit over a single data transfer path between them, desired identical records on the synchronized DASDs are concurrently located while the DASDs are reconnected to the data transfer path. Upon locating the desired identical records, the DASDs are reconnected to the data transfer path. Then, a write command is transferred from the CPU to the control unit form concurrently recording the same data onto the synchronized DASDs at the desired record locations.
The Murase Patent discloses a tape dubbing apparatus in which each of a plurality of slave recorders is operated in synchronism with a master player. Each slave recorder has at least one rotary magnetic head for repeatedly scanning a respective magnetic recording tape and receiving from the master tape player a signal to be recorded along with an external sync or reference signal. Each slave recorder is provided with a respective time base adjusting memory in which the signal to be recorded is written in synchronism with the external reference signal and from which the signal to be recorded is read-out in synchronism with a reference pulse generated in timed relation to a predetermined rotational position of the respective rotary magnetic head.
The DuLac Patent discloses a digital data bus architecture for a computer disk drive controller. The disk drive controller bus architecture enables the controller to be interfaced with disk drives having widely varying data format requirements in a configuration that is user-programmable and implementable on a single semiconductor chip. The bus architecture comprises a disk drive parameter storage section, a disk drive parameter comparator/interface section and a set of associated data buses, coupled between a disk drive control processor and the disk drive.
The Dahlerud Patent discloses a method and apparatus for accessing peripheral storage with asychronized individual requests to a host processor. The apparatus duplicates data from multiple magnetic disks and tapes, where the host processor functions as a data source and a plurality of peripheral storage devices function as data receivers, and are connected to one another via a data bus and a control bus.
The Kahn Patent discloses a serial data transmitter with dual buffers operating separately and having scan and self test modes.
The Ishii Patent discloses a recording data producing system for an optical recording. The audio information and the video information are converted by a computer into the information conforming to the CD-I data format, in which the amount of the converted software corresponds to at least the capacity of an optical disc and is stored in the memory.
In summary, there are three most common methods developed by the PC industry to address the need of duplicating HDDs: (1) Using the operating system to copy a source HDD to a target HDD; (2) Using a network to copy files from a centralized source HDD to many computers. Each computer includes one target HDD; and (3) Using a specialized duplicating device to copy a source HDD to many target HDDs at the same time.
The first method utilizes the operating system of a PC to copy HDDs. It first prepares a master HDD with the application programs. This master HDD is used as the source HDD. Once the source HDD is available, the user activates the computers' built-in functions to copy files from the source HDD to a designated Target HDD. The typical PC allows for only two HDDs to connect to the same interface cable, so duplicating HDDs must be done one at a time. The HDDs have to be configured by moving few jumpers on the master and target HDDs. However, there is often a compatibility problem because not all HDDs work with all other HDDs. This single copy process is also very time consuming because the file content is transferred from the source HDD to the computer memory first, and then transferred to the target HDD. For example, copying 200 MB from one drive to another using a high performance PC and disk drives takes about 9 minutes.
The second method utilizes a network to copy HDDs. It first prepares an image of the HDD on a centralized file server. Once the image is available, the user activates the computers' built-in functions with the network access functions to copy files from the file server, via the network, to the target HDD. This method is most suitable when the HDD is installed in the computer's enclosure as part of the PC manufacturing process. The HDD is not removed from the computer enclosure. The method is also time consuming because the HDD has to be first initialized to be recognized by the computer, and the file content is transferred to the computer memory first, and then transferred to the target HDD. Also, the computer must have a network connection installed for the duplication process to take place. However, network connection is not a standard feature of the PC.
The third method utilizes a specialized duplicating system. It first prepares a master HDD with the application programs. This master HDD is used as the source HDD. Once the source HDD is available, the user activates the duplicating system's functions to copy the files from the source HDD to many designated target HDDs. A high cost duplication system allows for up to 16 target HDDs to be created at the same time. A moderate cost duplication system allows for up to 4 target HDDs to be created at the same time.
There is still a need for a reliable high speed and low cost portable duplicating device for generating multiple copies of the same data and recording them onto multiple HDDs, which can be used in connection with a PC as a user interface for controlling the duplication process.